The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Diesel engine operation involves combustion that generates exhaust gas. During combustion, an air/fuel mixture is delivered through an intake valve to cylinders and is combusted therein. After combustion, the piston forces the exhaust in the cylinders into an exhaust system. The exhaust may contain emissions such as oxides of nitrogen (NOx) and carbon monoxide (CO).
An exhaust treatment system is typically used to reduce vehicle emissions. A diesel particulate filter can be used in the exhaust system for diesel engines. The diesel particulate filter removes particulate matter from the exhaust. The particulate matter is often referred to as soot. A diesel-powered vehicle equipped with a functioning filter will emit no visible smoke from its exhaust pipe.
The exhaust treatment system may also include a particulate matter sensor. The particulate matter sensor detects particulate matter flowing in the exhaust. Based on a signal from the PM sensor, a control module can monitor the performance of a particulate filter and determine the amount of particulate matter being released into the atmosphere.